1. Field of the Invention
The present invention relates to an endoscope having a suction control unit for sucking, for example, waste in a body cavity, cleaning water injected, etc., and removing them.
2. Description of the Related Art
Published Examined Japanese Utility Model 128 Registration corresponding to U.S. Pat. No. 4,412,531 and Published Unexamined Japanese Patent Application 63-214228 disclose known ordinary endoscopes whose suction control unit includes a cylinder incorporated into a control section and a control piston inserted into the cylinder and having a suction tube leading to a suction unit and suction channel for the endoscope which are connected to the cylinder.
One end of the suction channel and one end of the suction tube are connected in a mutually orthogonal relation to the cylinder. For this reason, upon the cleaning of the suction tube, a cleaning brush is externally pushed into the cylinder so as to force waste into the cylinder. Then the brush is inserted via the opening side of the cylinder to allow the waste to be discharged out of the distal end of an insertion section.
If a sequence of operation is wrongly done, it is sometimes impossible to completely discharge remaining waste out of the whole tube. Further, the operation sequence is also important from the standpoint of preventing the infection of diseases, etc. Since the suction channel and suction tube are connected in an orthogonal relation to the axial direction of the cylinder, it is cumbersome to perform a cleaning operation by the cleaning brush.
Published Unexamined Japanese Patent Application No. 63-203127 discloses an endoscope having a suction control unit of such a type that a suction channel and a suction tube leading to a suction unit are provided in a parallel relation, but that they have to be individually connected to a corresponding connector body. The arrangement includes, in addition, an elastic control valve, etc., and becomes complex and hard to clean by a cleaning brush. In particular, the control valve per se is liable to be soiled with deposited waste, thus leaving something to be improved.